This invention relates to double containment piping, and more particularly to fabrication of double containment polymeric piping components and systems.
Double containment piping systems are used for a variety of purposes, one of which is for safety reasons, the outer conduit serving as a container for any leakage of fluid, e.g., chemicals, from the inner conduit. The outer conduit is typically substantially larger than the inner conduit, so that there is a significant space between them. This space is typically maintained by annular spacers. Although double containment piping systems are highly useful, a substantial difficulty with such systems is that of assembly. The inner conduit components, including elbows, nipples, couplings and pipe, must be assembled inside the outer conduit components, hoping that all connections on the inside are sealed so as to be leakproof. Making assembly connections and sealed joints is particularly complex and labor intensive. Labor intensive operations involve three particular concomitant disadvantages, the first being increased percentage of human error, the second being significantly higher cost, and the third being the tediousness of the labor. The connections can be bonded together by a solvent-type adhesive, or by fusion bonding or welding. The former releases solvent fumes while the latter requires manual labor to make blind joints.